Method for bifurcating blanks



' R. L. WILCOX. METHOD OF BIFURCATING BLANKS.

APPIJICATION FILED JAN- 2i. 1920.

Patented Aug. 1, 1922.

RICHARD LESTER WILCOX,

PATT

OF WATERBURY, CONNECTICUT, ASSIGNOR TO THE VIA'IERBURY FARR-EL FOUNDRY AND IEACHINE COMPANY, 9F X/VATERBURY, CQNNECTICUT, A CORPORATION OF CONNECTICUT.

IdETI-IOD FOR BIFURCATING BLANKS.

Specification of Letters Patent.

Patented Aug. 1, 1%22.

Application filed January 21, 1920. Serial No. 353,122.

To aZZ whom it may 00m 061%:

Be it known that I, RICHARD LESTER VVIL- cox, a citizen of the United States, residing at l Vaterbury, in the county of New Haven and State of Connecticut, have invented certain new and useful Improvements in Methods for Bifurcating Blanks, of which the following is a specification, reference be ing had therein to the accompanying drawings.

My invention relates to a new and improved method for bifurcating blanks, by cutting in the end thereof a slot having the sides thereof tapered toward each other as they approach the head of the blank.

It is the object of this invention, among other things, to perform the necessary operations with tools that are of standard size and shape, readily procurable in the open market and which will produce the desired result with the minimum amount of cutting strain upon the blank and by so arranging the cuts that only a portion of the material removed is actually engaged by the cutting tools.

To these, and other ends, my invention consists in the method for bifurcating blanks substantially as herein shown and described but which may, however, be practiced in various other ways and still produce the same result.

Referring to the drawings, in which like numerals of reference designate like parts in the several figures;

Figure v1 represents a blank with one of the cuts partially completed and showing the cutting tool in broken lines;

Figure 2 is a similar view with the out shown in Figure 1 extended to the head of the blank, the cutting tool also being shown in broken lines;

Figure 3 is a similar view after a subsequent operation with a slot in the shank thereof similar to that shown in Figure 1, except on the opposite side of the center thereof Figure 4 is a view of the blank after the operation substantially similar to that shown in Figure 2 has been completed but upon the opposite side of the center thereof; and

Figure 5 is a view of the completed blank.

l-Ieretofore it has been the practice to cut the slot in the end of the blank, for the purpose of bifurcating it, by tools that were of special design, shape and structure, costly to make, easily injured or destroyed and oper ated so as to remove all of the material by actual contact with the cutting tool. By this practice a considerable strain is placed upon the blank by the tool that takes at a single cut a chip of the full width of the slot at its widest part, that is at the end of the blank. With my invention a comparatively narrow slot is cut in the end of the blank at the same angle as the side of the slot and is subsequently extended to the bottom of the finished slot. The cuts to accomplish this result are made with a tool of standard size and readily obtainable in the open market. Similar cuts are made in the blank on the opposite side of the center thereof and join the cut first mentioned near or at the bottom of the slot. This releases a portion of the material between the cuts which drops out and leaves the finished blank with the slot of the required width and depth and all of the material removed with the minimum of strain thereon.

in the drawings I have illustrated a blank of a common type having a shank 10 and a head 11, this latter being of the rounded type but, of course, it may be fiat or many sided, as may be desired, the shank being the portion operated on by the method herein described.

The first step of this method is to cut a slot 12 in the shank of any desired depth, but as shown of substantially half the depth of the full slot. Then extend this slot at 13 either by the cutter 19 shown in Figure 1 or by a series of cuts with cutters of substantially the same size and shape.

By these cuts one wall i l of the finished slot is completed as the cutter operates in the same plane as said wall. The same charactor and series of operations are performed upon the opposite side of the blank, that is, a slot 15 first being formed therein, subsequently this being extended at 16 to make the full depth slot, the outer wall 17 of these latter cuts being one wall of the finished slot.

The slot 16 at its lower end runs into the slot 13 thereby releasing the portion of the blank designated 18 which now being released drops out.

As the cuts are made with cutters of standard size and shape, only a minimum pressure is necessary to hold the blank during the which comprises slotting the blank with cuts cutting operations, and by the joining of the at an angle to the length thereof which join slots 16 and 13' a substantial portionof the at the inner ends. shank is released and removed at the same 2. The method for bifurcating blanks time without being engaged by the tools. which comprises slotting'the blank with cuts The cutter 19 herein shown is circular and at an angle to the length. thereof and by such comparatively narrow in width, being less cuts releasing a portion of the blank. than the width of the finished slot at its nar- 3. The method for bifurcating blanks, rowest point. It may, however, be of greater comprising the cutting of a slot in said blank thickness, but preferably not widerthan the by a plurality of cuts of less width than the finished slot at its narrowest point. While 1 slot, two of said cuts at the bottom of the slot have. described the slots 12 and 13 being running into each other and releasing that made byseparate cutters, this is not essential portion of the blank therebetween. as aasingle cutter can perform the operation 1. The method for bifurcating blanks if desired, this being determined sometimes comprising the producing of a slot in said by the length of the blank, and also if deblank of greater width at one end than at sired even three or more cutters canbe. used the other, with cuts of substantially'uniform for successive cuts. width, one side of each of which forms one Having described my invention, what I of the sides of saidslot. I claim asnew and desire to secure by Letters In testimony whereof, I have, hereunto Patent is: affixed my signature.

, lLThe zmethod for bifurcating blanks RICHARD LESTER VVILCOX. 

